Traditionally, absorbent products, such as sanitary napkins, diapers, incontinence pads and the like, contained an absorbent core comprised of a soft, fluffy material, such as comminuted wood pulp. Recently, attempts have been made to incorporate various secondary material into the absorbent fluff, such as superabsorbent particles, heat stabilizing fibers, or odor absorbent material.
Unfortunately, the methods used heretofore to produce an absorbent fluff core containing such a secondary material have not been entirely suitable. Typically, a first layer of absorbent fluff is formed and a layer of the secondary material is sprinkled on top of the fluff. A second layer of absorbent fluff is then placed on top of the secondary material to complete the core. As a result, this method produces a product in which the secondary material is concentrated in fairly discrete zone within the core. In the case of superabsorbents, this concentration results is a tendency toward "gel block," whereby the swelling of the superabsorbent particles inhibits the distribution of fluid throughout the core. In the case of heat activated fibers, the concentration of heat activated fibers in a discrete layer creates an uncomfortably stiff product.
Consequently, it would be desirable to provide an apparatus and method for making absorbent products comprised of first and second materials in which the second material (i.e., superabsorbent particles) was well distributed throughout the first material (i.e., absorbent fluff). It would also be desirable to provide an apparatus and method for making absorbent products comprised of first and second layers in which the first layer contained pure first material and the second layer contained a mixture of the first and second materials.